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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

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Old 6th Feb 2010, 6:34 pm   #1
jazzy
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Default 8 diode bridge rectifier?

Hello
I have a old rf valve amplifier which has 8 diodes what make up a bridge rectifier circuit, i don't think this is a doubling circuit.
Why then has 8 diodes been use instead of the usual 4 ?
Thany you
Garry
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Old 6th Feb 2010, 6:45 pm   #2
valvekits
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Default Re: 8 diode bridge rectifier?

Garry
I think this might be a way of increasing the Peak Inverse Voltage rating, assuming that there are four pairs of series connected diodes.

Eddie
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Old 6th Feb 2010, 6:52 pm   #3
Michael Maurice
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Default Re: 8 diode bridge rectifier?

I assume the diodes are semiconductors. It is indeed a way of doubling the PIV, i've seen this used in several applications.
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Old 6th Feb 2010, 7:03 pm   #4
jazzy
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Default Re: 8 diode bridge rectifier?

Thank you both for getting back to me ,yes there are two set of 4 diodes next to each other. I replaced them for higher rating as the first set fouled (was 500v now 1000v)
Thank you again
Garry
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Old 6th Feb 2010, 7:09 pm   #5
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Default Re: 8 diode bridge rectifier?

Just a thought why not just use higher rated diodes instead to increasing the Peak Inverse Voltage rating And why the need?
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Old 6th Feb 2010, 9:43 pm   #6
G8HQP Dave
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Default Re: 8 diode bridge rectifier?

How old is it? Early semiconductor diodes did not go to high voltages, so doubling up was quite common.
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Old 7th Feb 2010, 9:35 am   #7
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Default Re: 8 diode bridge rectifier?

Indeed! It was not uncommon to use two semi-conducter diodes in series for just a simple half-wave rectifier. The early diodes did not have the high PIV of later types. With a bridge rec, there would quite often be two diodes in series on each 'leg'.


Rich
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